That's why I listed what I used it in, I wondered if it would work on European actions or was more fit for the generic Remchestavages that many of Sinclair's customers are shooting, particularly high-grade M700 style actions. As for the muzzle down, yep, that's part of the deal, but I never thought it was a big problem. If I didn't own the Sinclair product I'd be adapting tresmon's method.
I have and use the Sinclair tool and like it a lot. I used tresmon's method for years using a 1/4" oak dowel and a sharp pencil. Either way works. The key to any measuring is consistency and a common datum point. In the case of the Sinclair tool, the datum point is the aft end of the delrin bushing.
